Device for modifying exhaust gases from internal combustion engines



June 1952 c. w. MORRIS 3,037,344

DEVICE FOR MODIFYING EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES Filed Feb. 23, 1960 2 Sheets-Sheet 1 J7 INVENTOR.

Cl/AQLES W Maze/s June 5, 1962 c. w. MORRIS DEVICE FOR MODIFYING EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet 2 Filed Feb. 23, 1960 INVENTOR. C/mez E5 W Maze/s flrroezvsys.

United States Patent 3,037,344 DEVICE FOR MODIFYING EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES Charles W. Morris, 11769 Chenault St., Los Angeles 49, Calif. Filed Feb. 23, 1960, Ser. No. 10,405 14 Claims. (Cl. 60-30) This invention relates to a device for reducing the content of hydrocarbons, carbon monoxide oxides of nitrogen and other noxious components in exhaust gases from internal combustion engines, and for increasing the temperature of such exhaust gases sufficiently to not only subject them to substantially complete combustion but also to prevent condensation of the exhaust gases in the muffiers, thereby eliminating corrosion. The invention also pertains to a compact, lightweight, inexpensive construction of a device which is free from numerous adjustable parts, is readily installed and is capable of eliminating those components generally attributed as the primary cause of air contamination, such contamination being commonly referred to as smog.

Studies have established that the contamination of the atmosphere in and around metropolitan centers is primarily due to the presence of hydrocarbon gases. It has also been established that the major contributingcause to such atmospheric pollution is the tremendous volume of hydrocarbon gases and carbon monoxide discharged into the atmosphere from the exhausts of automobiles and other vehicles driven by internal combustion engines. During idling and deceleration the exhaust gases carry very large quantities of hydrocarbons and of carbon monoxide; during acceleration and at ordinary cruising speeds the hydrocarbon content of the gases is not excessive. In metropolitan areas the progress of an automotive vehicle is a succession of idling periods interspersed with bursts of acceleration and periods of rapid deceleration; as a result, extremely large quantities of carbon monoxide and hydrocarbon vapors are discharged into the atmosphere. Research has shown that during deceleration as high as 55%-60% of the fuel is actually pumped out of the exhaust system in an unburned condition.

The extremely detrimental effects of this smog upon the health of the population, animals, vegetable growth, visibility etc. has become evident to almost all of the inhabitants of a metropolitan area. Many attempts have been made to minimize the effects of this smog. Many attempts have been made to modify the gases discharged from the exhausts of internal combustion engines, but prior attempts in this direction have involved complicated arrangements, the utilization of catalysts, and other expensive installations which are neither feasible nor 7 practical.

The flexibility of an internal combustion engine introduces a number of problems. The operating conditions of an internal combustion engine may be classified as idling, deceleration, acceleration and cruising speeds; the hydrocarbon content of exhaust gases varies greatly under these different operating conditions. For example, during idling and deceleration the hydrocarbon content of the exhaust gases is high whereas during acceleration and cruising the hydrocarbon content is relatively low. An average internal combustion engine of the character used in an automobile may carry 400 p.p.m. of hydrocarbons in its exhaust during idling. This may drop to 200 p.p.m. during acceleration and cruising but during deceleration the hydrocarbon content of the gases being exhausted may readily reach 5500 p.p.m. Similarly, the carbon monoxide content of the exhaust gases may vary from 6% during idling, to 2 /2% during acceleration, to 0.5% during cruising and rise to 4% during deceleration. It is to be remembered that temperatures above 1200 F. are re quired to cause combustion of carbon monoxide; temperatures of 1500 to 2000" F. are necessary in order to obtain complete combustion of carbon monoxide. The exhaust temperature (at the outlet of an exhaust manifold of an internal combustion automobile engine) may vary from 400600 F. during deceleration to about 800 F. during idling, 800-900 F. during cruising speeds and reach temperatures of ll00l200 F. during acceleration. None of these temperatures are sufficiently high to actually burn or cause combustion of carbon monoxide,

- Another variable which must be taken into consideration comprises the volumetric flow of exhaust gases; the volumetric flow is ordinarily low during idling and deceleration but is high during acceleration and cruising. Moreover, the pressure of the exhaust gases also varies within wide limits. The pressure of the exhaust gases is ordinarily low during idling and deceleration but is quite high during acceleration and cruising.

These varying characteristics of an internal combustion engine and its exhaust gases present problems which have been deemed insurmountable heretofore. As previously indicated prior attempts have involved such complicated systems and such material modifications of the normal carburetors, cooling systems etc. as to render the prior devices totally unacceptable. A device capable of being used on millions of automobiles and trucks must be sirnple and effective Without the necessity of employing an engineer to operate the device; the average owner of an automobile is not in position to spend a large sum of money upon a device of a complicated nature requiring hours of labor in order to adapt and install the device to his vehicle.

The present invention is directed to a device which may be installed not only on new vehicles but also on cars and trucks now in service. It is to be remembered that for every new automotive vehicle there are approximately seven vehicles of older vintage now in service and it is essential that these older vehicles be equipped with devices which correct, ameliorate and render innocuous the exhaust gases being discharged thereby. The present invention is therefore directed to a device which is readily attached to automobiles and trucks now in service; it is directed to a small compact device which does not require modification of existing vehicles. The invention is directed to a device which is capable of effectively destroying or minimizing'the hydrocarbon and carbon monoxide content of exhaust gases from internal combustion engines without requiring periodic charging with fresh catalyst or regeneration of catalyst.

The present invention furthermore is directed to a device in which operative temperatures are rapidly reached so that the device operates effectively in a period of time which is shorter than that required for the usual water jacket temperatures to reach optimum. It relates to a device that can be manufactured economically in large quantities, sold at a reasonable price and installed by any mechanic without difliculty. It does not require the attachment to or interference with carburetors or cooling systems. It does not impose a drain upon the electrical system of a vehicle. It is not necessary to have a device of the present invention of a different size for internal combustion engines which differ in volumetric displacement by as much as the same device can be ad justed and effectively used on either a four-cylinder, sixcylinder or eight-cylinder engine.

One of the objects of the present invention is to disclose and provide a small, compact, inexpensive device which may be readily attached not only to new internal combustion engines and vehicles employing the same but which can also be readily adapted and attached to existing vehicles employing internal combustion engines for the purpose of reducing the hydrocarbon and carbon monoxide content of exhaust gases discharged from said engine.

Another object of this present invention is to disclose and provide a small compact and simple device which does not employ catalysts and in which operative temperatures are rapidly reached so that the major proportion of carbon monoxide contained in the exhaust gases may be consumed and burned, the temperature of the exhaust gases being thus increased sufficiently so as to prevent condensation of exhaust gases in the mufflers of the vehicles, thereby increasing the life of such mufilers.

A still further object of the invention is to disclose and provide a device capable of burning exhaust gases with air added in approximate accordance with variation in the hydrocarbon content of said gases under different operating conditions of the engine, such variation being accomplished automatically and without the use of com-.

plicated or expensive machinery or instrumentation.

Again an object of the present invention is to disclose and provide a device for modifying the hydrocarbon and carbon monoxide content of exhaust gases from an internal combustion engine, a device of substantially the same size being adaptable to internal combustion engines which differ in volumetric displacement by as much as 100%.

Moreover, the present invention is directed to a device for modifying and correcting the hydrocarbon and carbon monoxide content of exhaust gases of internal combustion engines, the device being inexpensive and capable of being readily installed by any mechanic without difficulty.

These and various other objects, uses and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of certain exemplary forms that this invention may assume in actual practice. In order to facilitate understanding, reference will be had to the appended drawings in which:

FIG. 1 is a diagrammatic side view of an internal combustion engine and its exhaust system equipped with one form of my device;

FIG. 2 is an enlarged axial section taken through one form of device of the character illustrated in FIG. 1;

FIG. 3 is a transverse section taken along the broken plane *III-III in FIG. 2;

FIG. 4 is a partial section taken along the plane IVIV in FIG. 2;

FIG. 5 is a simplified drawing illustrating a modified form of device, which may be factory installed on new automobiles.

FIG. 6 is a partial section of another form of device, as a part of an exhaust manifold, including means for converging fumes from a crankcase into the device.

FIG. 7 is a still further modification.

The ease with which the device of the present invention may be installed in a conventional internal combustion engine-exhaust system is exemplified by FIG. 1. As there shown, the internal combustion engine 1 is provided with the usual exhaust manifold 2 having an exhaust outlet 3. Ordinarily such exhaust outlet is connected as by means of a pipe 4 with a mufller 5. The present device, generally indicated by the numeral 10, is attached to and interposed between the exhaust muffler 2 and the exhaust pipe 4. A portion of the normal exhaust pipe 4 may be cut away and means provided for attaching the device 10 so as to be in the path of the normal exhaust gases from the manifold. Such installation may be accomplished by any mechanic and by the use of suitable adapters, variations in diameter of exhaust pipe, etc., may be readily compensated for. The presence of auxiliary equipment to the side of the internal combustion engine 1 (such as generators, batteries, etc.) does not interpose an obstacle since the device 10 may be placed in different position so as to avoid such auxiliary equipment, for example, in the position indicated by dash lines at 10'. The entire device 10 occupies not more than one-half cubic foot of space and generally only about one-third of a cubic foot of space, and such small volume can be readily installed in a number of positions along the exhaust pipe 4 between the exhaust manifold 2 and the muffler 5.

Although a device embodying the mode of operation of the present invention may assume many forms and modifications, the exemplary form shown in FIGS. 2, 3 and 4 is simple, effective and illustrates the teachings of this invention. My device, generally indicated at 10, includes a hollow connector fitting 12 which may be made of two stamped metal halves, each provided with flanges 13 and 13 the flanges being connected (as by spot welding) to make the connector sufficiently rigid. One end of fitting 12 is provided with port 14 for connection to a source of exhaust gases, as an exhaust manifold; a side port 15 directs such incoming gases into the device 10; lower port 16 constitutes an outlet for treated gases and such outlet port 16 is generally connected to the exhaust pipe leading to a muffler of customary construction. It is to be understood that adjacent the ports 14 and 16 the fitting may be provided with flanges, adapters or other expedient means for attaching the fitting to pipe of different diameters, flanged manifold parts, etc. Such expedients are within the skill of a mechanic.

It may be noted that an externally extending, headed connector bead 17 is circularly arranged around port 15 in order to facilitate attachment of device 10 to such port. Moreover, the fitting 12 is provided with a cylindrical guide 18 which is coaxial with port 15. The guide 18 may carry a flange 1 9 which acts as a limit stop for an unbalanced butterfly valve 20, carried by pivot axis 21. The valve 20 and flange or stop 19 normally guide exhaust gases from port 14 to port 15 during idling and deceleration, the valve being in the position shown in full lines. The valve is biased into this full line position by a spring or an adjustably positionable weight W on arm 22 connected to pivot pin 21. The end of arm 22 opposite the weight may be pivotally connected at 23 to link 24 which is, in turn, pivotally connected at 25 to crank 26. Crank 26 is mounted on one end of rod 27 (which is journaled in the side walls of the connector fitting), the rod 27 having an eccentric actuating pin 28. The operation and utility of this arrangement will become apparent subsequently.

The main portion of device 10 is virtually conical in longitudinal section and circular in transverse section. Centrally disposed within the device is a burner member defining and enclosing a burner chamber 34; the burner member is substantially conical and comprises an imperforate conical wall portion 35 adjacent the smaller open outlet end 36 and an enlarged conical end portion having the ported wall portion 37. A cylindrical extension 38, connected to wall portion 35, carries gases from the open outlet port into fitting 12, the cylindrical extension 38 being slidably received in guide 18. The enlarged end of the burner chamber 34 is closed by means of a transverse partition 40 attached to the housing 41.

In the form of device illustrated, the housing 41 is shown as being double-walled and including an inner wall 42 and an outer wall 43, these walls being in spaced relation. Inner wall member 42 may be formed as by spinning from tubular or conical stock, carries the transverse portion 40 at its enlarged end and is partitioned by attaching the smaller end to headed connector 17 adjacent port 15. The inner surface of housing wall member 42 is in spaced relation to the outer surface of the smaller imperforated wall portion 35 of the burner member and cooperates therewith to provide an annular gas intake and venturi throat 45 around the outlet end of the burner member. The included angle of conical wall portion 35 of the burner member is smaller (say 40-46) so that gases admitted through annular inlet 45 and the venturi throat pass into an enlarged expansion difiusion and preheating chamber '46. The larger and outer end portion of housing wall member 42 may be cylindrical and is in contact with the marginal large end portion of the burner member, thus directing gases from the diifusion and preheating chamber 46 through the ported Wall portion 37 into the burner chamber 34. Partition carries a spark plug '50 (or other igniting means) extending into the burner chamber.

Outer housing wall member 43 may be formed in two halves which may be joined along an axial plane by spot welding outstanding parting plane fins or in any other suitable manner. The smaller, inner end of wall member 43 may grasp connector 17 or be connected to fitting 12 in any other manner. The outer end of housing member 43 is provided with an air intake port 47. The outer housing member 43 is spaced from the inner wall member '42 and air from intake port 47 may flow through such space between the walls to the annular chamber 48 formed around the venturi throat and be discharged into the stream of gases passing at high velocity through such throat through a plurality of spaced ports 49 of constant cross section. Suitable spacing between housing wall member 42 and 43 may be established by scattered inwardly extending deformations in Wall member 43, use of spacing pins etc.

A protective weather cap 51, having a large opening in one side may be carried at the air intake port 47. The entire housing is preferably covered with high-ternperature heat insulation 52 (such as matted glass fiber or asbestos) and an external layer of rigidized metal foil 53 (metal foil and wire mesh).

From the description given, it will be observed that hot exhaust gases from an internal combustion engine admitted through port 14 of the fitting will pass through the annular port 45 into the throat of the venturi and air (admitted through intake 47 into annular chamber 48) will be sucked in preheated form through ports '49 into such stream of exhaust gases. This mixture of gases is mixed and further heated in difiusion chamber 46 and their velocity is greatly reduced by the time the mixture passes through the burner chamber 34. The mix-ture is ignited by the spark plug in the burner chamber and is discharged through the relatively small outlet 36 into the fitting and out the outlet port 16. It is not necessary to use flame arresters in the burner chamber since the volume is suflicient to reduce the velocity of the gases (in the upper and larger end of the chamber) to below flame-propagation velocity.

In order to facilitate the maintenance of high temperatures within the burner under difiFerent operating conditions and enhance heat exchange, a piece of expanded metal lath or other arrangement of heat resisting metal or alloy (having mass but not ofiering resistance to flow of gases therethrough) may be placed in and across the burner chamber 34 to contact the larger end walls of covered portion 35, such metal liberating radiant heat and enhancing mixing of the gases.

Exhaust gases from an internal combustion engine which is under cruising load or which is accelerating are at relatively high temperatures (8001200 F.) and contain relative low proportions of hydrocarbons and carbon monoxide. A very small proportion of air need be added to such exhaust gases, which will be supplied to the device in relatively high volume and pressure. During idling and deceleration exhaust gases are at lower temperatures (400-80Q F.), are supplied in lower volume and at low pressures but carry a high proportion of hydrocarbons and a large proportion of air need be mixed therewith to assure combustion. Means are provided whereby an adequate amount of air is admitted at all times to maintain combustion in the burner chamber under all engine load and operating conditions, by maintaining an air intake of constant cross-sectional area. In the illustrated device air intake 47 is always open and ports 49 are always open and of constant cross section. Means are also provided to vary the proportion of air sucked mto the exhaust gases inversely with respect to the flow of exhaust gases through the venturi. This inverse relationship is not mathematically perfect, but is an approximation; the means of this invention permit addition of air in approximate accordance with the variation in hydrocarbon content of the supplied gases under diiferent operating conditions of an engine. Again attention is drawn to average automobile engine exhausts. During acceleration we have high volume gas fiow and only about 200 ppm. of hydrocarbons in the exhaust gases. During deceleration we have low volume gas flow and 5000-5400 ppm. of hydrocarbons.

In accordance with the mode of operation of my invention, the device can be regulated and controlled and the hereinabove inverse relationship can be obtained by by-passing some exhaust gases or by controllable relative movement between the housing and burner member. In the form illustrated, the burner member (and particularly imperforate wall 35 thereof) can be moved axially with respect to the housing wall member 42 to effectively vary the width of the throat of the annular venturi and thereby, by increasing the throat width, larger volumes of exhaust gases can pass therethrough and a smaller relative proportion of air will be added thereto. When the throat width is reduced, smaller volume of gases may pass therethrough at the same velocity, so that a larger proportion of air is added to such gases.

Movement of the elements with respect to each other to attain the benefits of this invention may be produced in a number of difierent ways. Such movement may or may not be accompanied by a bypassing of proportion of exhaust gases directly into the usual muffler system, thereby reducing the load on my device. Such axial movement may be imparted to the burner member of my invention by volumetric changes of a temperature sensitive device responsive to temperature variations in the exhaust gases being discharged by the internal combustion engine, or by a pressure-sensitive device responsive to pressure change in such exhaust gases (note: exhaust gas pressures during acceleration and cruising are five to ten times as great as during idling and deceleration), or by devices sensitive to variations in volumetric flow, or by a combination of devices.

In the device of FIGS. 2-4, the cylindrical extension 38 is provided with a medial fin 30 having a notch 29 through which eccentric 28 extends. During acceleration and cruising, or whenever high flow and high pressure conditions exist in the exhaust gases supplied to port 14, unbalanced or biased valve 20 will move into partly open position and such movement is translated (by link 24, arm 26 and eccentric 28) into axial movement of the burner member, such movement increasing the width of the venturi throat and thereby reducing the proportion of air sucked into the gases traversing such throat. Simultaneously, a portion of the incoming exhaust gases are caused to bypass the device, the partially open valve permitting some gases to pass directly from inlet 14 to outlet 16.

The width of the throat in the venturi varies (during operation) by less than 0.1 inch and is preset for minimum width and optimum efliectiveness, which may be on the order of only 0.0400.050 inch. Such minimum setting can be readily obtained by a Vernier stop such as set screw 31 threadedly held in the threaded bore of an insert 32 carried by the wall of fitting 12. The conical end 33 of the set screw acts as an adjustable stop against the end of fin 30.

It is to be understood that the spark plug is connected to the electrical system of the engine and is energized whenever the ignition system is turned on. The burner member and at least the inner wall member of the housing is made of heat-resisting metal or alloy since temperatures as high as 2000 F. are reached in the chamher 34. Nickel alloys or chrome-treated steel have been found effective. The device may be placed in any desired position; it occupies less than one-half cubic foot of space (for automobile engine use). Effective treatment of exhaust gases can require the addition of from two to five cubic feet of air per minute.

Devices embodying the heat-exchange relationships and mode of operation of this invention may take many forms. In simplified form, the conical combustion chamber is located in an optimum position of venturi clear ance and the opening of the bypass valve under influence of the higher pressures induced by higher exhaust gas flows prevents the introduction of excessive amounts of air at the venturi in relation to the total exhaust flowing from the engine. This arrangement also makes the venturi sensitive to providing adequate air induction at low exhaust gas flows without serving as a block to high exhaust gas flow condition and impairing engine performance. FIG. shows this arrangement. When made as an integral part of a new engine or automotive sys tem, the device may assume the form illustrated in FIG. 5.

The device illustrated in FIG. 5 is a part of an exhaust manifold 2 and is mounted with the cylindrical extension 38 of the burner member axial with respect to manifold outlet 3'. The cylindrical outlet extension may be slidably received by a guide sleeve 54 held by a spider unitary with the manifold outlet. The outlet extension may carry an obturating element 55 arranged to close the manifold outlet during low pressure conditions in the manifold. The outer housing 53 is single walled and cooperates with the conical burner member to form venturi intake 45 and an expansion zone 46'. (The same numbers are being used on similar parts in order to facilitate comparison and understanding.)

The entire device is supported over a port 8 formed in the exhaust manifold, by a cylindrical, pressure-responsive bellows 56. The ends of the bellows are connected to the manifold and the outer housing of the device.

The device of FIG. 5 differs from the previously described device in that the burner member carries an annular air chamber 49 which is supplied with air by tube 57 extending through the burner chamber and into the atmosphere. A plurality of spaced, fixed orifice ports communicate the annular air chamber with the venturi.

The operation of a device of the type shown in FIG. 5 can be readily understood in the light of the preceding discussion. During idling and deceleration all of the exhaust gases pass through the venturi, pick up air, expand, pass into the enlarged burner chamber, are ignited and then discharged through the outlet and exhaust pipe attached to the exhaust manifold outlet. During acceleration and cruising, the exhaust gases are at a materially higher pressure; this pressure expands the bellows and raises the device so as to partially open the manifold outlet port and bypass a portion of the gases.

FIG. 6 is a more sophisticataed form of device shown installed in an exhaust manifold. The arrangement of inner and outer housing wall portions and axially contained and movable burner member is the same as in FIG. 2. The headed connector 17' is now a part of an open cage 58 having a bottom 59 which normally rests on and closes the manifold outlet. Such bottom is provided with a tubular extension 60 in which the cylindrical extension 38" of the burner chamber is slidably received; such tubular extension, in turn, is slidably received in guide sleeve 54, of the manifold outlet.

The outer housing portions (and open cage 58) are supported by the expandable bellows 56' which surround port 8' in the manifold. The housing may be provided with an outstanding ring 60, guide rods 61 being carried by the manifold and extending through such ring. Springs bearing against such ring and adjustable stops on the guide rods limit and modify the action of the bellows.

Each of the rods 61v may extend into the manifold and act as a fulcrum point 62 for a lever 63 which is also pivotally connected at a pivot pin support 64 to cage 58, the inner end of the lever being forked and grasping an annular bead or flange 65 carried by the outer surface of the cylindrical extension of the burner member. Fulcrum 64 .should be closer to the forked end than to the fixed pivot 62.

In operation, the device of FIG. 6 causes all exhaust gases to pass through the venturi during low gas pressure, idling or deceleration conditions. During acceleration (or while running under load) the bellows expands and raises the housing and cage 58 thereby bypassing some exhaust gases directly into the manifold outlet. Levers 63 simultaneously move the inner burner member with respect to the housing so as to increase the effective width of the venturi, for purposes and with the results hereinbefore explained.

Fumes and gases are usually discharged from a crankcase through the oil filling aperture. During acceleration, combustion gases blow by the pistons into the crankcase and the blowby gases from the oil-filling vent may amount to 1.6 c.f.m. with a hydrocarbon content as high as 6000 ppm. My invention contemplates conducting such blowby gases from the crankcase to the atmospheric air intake of my devices, to consume such hydrocarbons, and thereby further prevent pollution of the atmosphere. Conduit 51' exemplifies a gas-conducting element whose other end is in communication with a vent from the crankcase.

FIG. 7 illustrates a further modification of the device shown in FIG. 2 in that a temperature responsive device 66 (which may be a bulb filled with a substance exhibiting expansion in the range of about 650-750 F.) is positioned in the exhaust manifold and connected, as by flexible pressure tube 67 to a bellows 68 which imparts axial movement to the inner burner member and thereby changes the effective width of the venturi throat. The temperature of the exhaust gases is low during idling and deceleration and under such conditions the venturi is not as Wide, gas velocities through it are high and an increased amount of air is sucked in. It will also be noted that a biased by-pass valve 20 is used, and the counterbalance arm 22 moves along an arc (in response to increase in exhaust gas pressure) which applies a differential torque to the valve shaft.

I claim:

1. A device for modifying the exhaust gases from an internal combustion engine by reducing their content of hydrocarbons and carbon monoxide and increasing their temperature sufiiciently to prevent condensation of exhaust gas components in a muffler, comprising: a housing coaxially containing a burner member, said burner member having an open outlet end and an enlarged inner end portion and defining a conical burner chamber, said burner member having an imperforate conical wall portion adjacent said outlet end and a ported wall adjacent the enlarged inner end; partition means closing the en larged end of the chamber defined by the burner member; said housing being in contact with the enlarged end portion of the burner member and in spaced relation to the outlet end to provide an annular gas intake and venturi throat around said outlet end portion of the burner member, said throat leading to an enlarged diffusion and preheating chamber between said housing and burner member; gas ignition means in the enlarged end portion of said burner chamber; means for admitting air to said venturi throat adjacent the diffusion and preheating chamber; means for supplying exhaust gases from said internal combustion engine to said annular gas intake and throat; and means for varying the effective width of the throat of said venturi to "vary the proportion of air supplied inversely with respect to flow of exhaust gases through said venturi.

2. A device as stated in claim 1 wherein said open 9 outlet end of the burner member is provided with a cylindrical extension; said housing which defines said enlarged diffusion and preheating chamber is provided with a conical wall portion having a greater included angle than the angle included by the imperforate conical wall portion of the burner member, and said varying means including means to impart controllable relative axial movement between the housing and burner member to vary the effective spacing therebetween at the throat of said venturi.

3. A device as stated in claim 1 wherein the means for admitting air to the throat of said venturi include ports in communication with an air intake of constant cross sectional area and the volumetric capacity of said burner chamber is sufficiently large to maintain the velocity of gases passing through the enlarged portion of the chamber below flame-propagation velocity.

4. A device for modifying. and rendering innocuous exhaust gases from internal combustion engines by subjecting said gases to high temperature combustion in the absence of added catalyst comprising: a diffusion and preheating chamber; wall means defining a venturi having a throat for admitting exhaust gases from an internal combustion engine into the diffusion and preheating chamber; a burner chamber in heat-exchange relation to said diffusion and preheating chamber, said burner chamber having an enlarged closed end portion and a smaller end portion provided with an outlet port; passageways for admitting gases from the diffusion and preheating chamber into the enlarged end portion of the burner chamber; ignition means in said enlarged end portion of the burner chamber; a plurality of constant cross section air ports in a wall of the venturi throat adjacent the diffusion and preheating chamber; means for continually supplying atmospheric to said air ports; means for changing the effective width of said venturi throat to vary inversely the proportion of sucked-in air to the volumetric flow of exhaust gases passing through said throat; and valve means for by-passing a portion of such exhaust gases in response to the physical characteristics of such exhaust gases whereby the proportion of air admixed with the total volume of exhaust gases is reduced when the total volume of exhaust gases is increased.

5. A device as stated in claim 4 wherein the diffusion chamber of the venturi and its throat are annular and the means for changing the effective width of said venturi throat comprise means for moving the walls of said venturi relatively to each other in response to changes in the volumetric flow of exhaust gases from said internal combustion engine and supplied to said venturi.

6. A device as stated in claim 4 wherein the diffusion chamber of the venturi and its throat are annular and the means for changing the effective width of said venturi throat comprise means for moving the walls of said venturi relatively to each other in response to changes in the temperature of exhaust gases from said internal combustion engine and supplied to said venturi.

7. A device as stated in claim 4 wherein the diffusion chamber of the venturi and its throat are annular and the means for changing the effective width of said venturi throat comprise means for moving the walls of said venturi relatively to each other in response to changes in the pressure of exhaust gases discharged by said internal combustion engine and supplied to said venturi.

8. A device for modifying and rendering innocuous exhaust gases from internal combustion engines by subjecting said gases to high temperature combustion in the absence of added catalyst comprising: a diffusion and preheating chamber; wall means defining a venturi having a throat for admitting exhaust gases from an internal combustion engine into the diffusion and preheating chamber; a burner chamber in heat-exchange relation to said diffusion and preheating chamber, said burner chamber having an enlarged closed end portion and a smaller end portion provided with an outlet port; passageways for admitting gases from the diffusion and preheating chamber into the enlarged end portion of the burner chamber;

ignition means in said enlarged end portion of the burner chamber; a plurality of constant cross section air ports in a wall of the venturi throat adjacent the diffusion and preheating chamber; means for continually supplying atmospheric air to said air ports; valve means responsive to increased pressure of exhaust gases generated during acceleration and cruising of such internal combustion engine for by-passing a portion of such exhaust gases and for eliminating such by-passing when exhaust gases are generated during idling and deceleration of such internal combustion engine; and means responsive to increased pressure of exhaust gases generated during acceleration for simultaneously increasing the effective width of said venturi throat and for simultaneously decreasing the effective width during idling and deceleration of such internal combustion engine.

9. A device for modifying and rendering innocuous exhaust gases from internal combustion engines by subjecting said gases to high temperature combustion in the absence of added catalyst comprising: a diffusion and preheating chamber; wall means defining a venturi having a throat for admitting exhaust gases from an internal combustion engine into the diffusion and preheating chamber; a burner chamber in heat-exchange relation to said diffusion and preheating chamber, said burner chamber having an enlarged closed end portion and a smaller end portion provided with an outlet port; passageways for admitting gases from the diffusion and preheating chamber into the enlarged end portion of the burner chamber; ignition means in said enlarged end portion of the burner chamber; a plurality of constant cross section air ports in a wall of the venutri throat adjacent the diffusion and preheating chamber; means for continually supplying atmospheric air to said air ports; means responsive to increased pressure of exhaust gases generated during acceleration for increasing the effective width of said venturi throat; and valve means responsive to increased pressure of exhaust gases generated during acceleration for by-passing a portion of such exhaust gases.

10. A device as stated in claim 4 wherein the means for continually supplying atmospheric air includes means for preheating the air by conducting such air in heat transfer relationship to the burner chamber and preheating chamber.

11. A device as stated in claim 4 wherein the means for continually supplying atmospheric air includes means for introducing blowby gases from a crankcase of an internal combustion engine.

12. A device for modifying and rendering innocuous exhaust gases from an internal combustion engine by subjecting said gases to high temperature combustion in the absence of added catalyst comprising: a diffusion and preheating chamber; wall means defining a venturi having a throat for continuously admitting exhaust gases from an internal combustion engine into the diffusion and preheating chamber; a burner chamber in heat exchange relation to said diffusion and preheating chamber and opening into said diffusion and preheating chamber, said burner chamber being partially defined and enclosed by the inner portion of the wall means defining said venturi throat; gas ports in the wall means of the venturi throat adjacent the diffusion and preheating chamber; means for continually supplying gas containing air; to said gas ports; ignition means in said burner chamber adjacent the opening of said burner chamber to said diffusion and preheating chamber for igniting the preheated, premixed mixture of gases containing exhaust gases and air and valve means responsive to the physical characteristics of the exhaust gases for by-passing a portion of said exhaust gases whereby during acceleration and cruising of said internal combustion engine a portion only of said exhaust gases is by-passed and during idling and deceleration such by-passing is eliminated.

13 A device for modifying the exhaust gases from an internal combustion engine by reducing their content of hydrocarbons and carbon monoxide and increasing their 1 1 temperature sufficiently to prevent condensation of exhaust gas components in a mufiler comprising: a housing coaxially containing a burner member, said burner member having an open outlet end and an enlarged inner end portion and defining a conical burner chamber, said burner member having an imperforate conical wall portion adjacent said outlet end and a ported wall adjacent the enlarged inner end; partition means closing the enlarged end of the chamber defined by the burner member; said housing being in contact with the enlarged end portion of the burner member and in spaced relation to the outlet end to provide an annular gas intake and venturi throat around said outlet end portion of the burner member, said throat leading to an enlarged diffusion and preheating chamber between said housing and burner member; gas ignition means in the enlarged end portion of said burner chamber; means for admitting air to said venturi throat adjacent the diflusion and preheating chamber; means for continually supplying exhaust gases from said internal combustion engine to said annular gas intake and throat; and valve means for bypassing a portion only of such exhaust gases in response to the physical characteristics of such exhaust gases whereby the proportion References Cited in the file of this patent UNITED STATES PATENTS 1,789,812 Frazer Jan. 20, 1931 1,848,990 Boyd et a1 Mar. 8, 1932 2,203,554 Uhri et al. June 4, 1940 2,488,563 Sills Nov. 22, 1949 2,772,147 Bowen et a1. Nov. 27, 1956 2,851,852 Cornelius Sept. 16, 1958 OTHER REFERENCES Textbook, Mechanical Engineering Practice, fifth edition, by Shoop and Tuve, 1956, published by McGraw- Hill Book Co., Inc., pages 241 and 245.

Rocket Encyclopedia Illustrated, by Aero Publishers, Inc., Los Angeles 26, Calif., 1959, page 561. 

